X-ray-beam generator



Nov. 1, 1927. 1,647,477 F. 5. SMITH X-RAY BEAM GENERATOR Filed Feb. 15. 1924 D "NVETOR 7 6 n'im Patented N... 1, 1921.

UNITED STATES PATENT OFFICE.

mm B. SUITE, BROOKLYN, m YORK, LBSIGIIQB To an PRODUCTS P- 4 MOTION CORPORATION, 01' m YORK, HZ. Y-, A OOBPOBA'IIOH OI nmwm Z-MY-m 6WD.

Application fled I'ebrury ii, an. Serial Io. 898,148.

This invention relates to the art of X-ray generation and it has for its general ob ect to provide an eiiicient apparatus capable of roducing a sin 1e X-ray beam or periodic -ray beams 0 high intensity and short duration. 7

Another object of the invent1on 1s to provide means whereby the periodicity of the X-ray beams may be greater than heretofore has been practical, as far as I am aware.

It is also an object of the invention to provide simple, reliable and efficient apparatus by means of which either a sin is X-ray beam or periodic X-ray beams of t e character indicated may be produced.

A further object of the invention is to provide means whereby the discharge circuit of a high voltage permittor comprising an X-ray tube is rendered automatically conducting whereby excitation of the said tube is effected.

Another object of this invention is to provide a thoroughly practical apparatus for controlling in a highly eflicient and thoroughly reliable manner the action of the X-ra tube energizing circuit. Another object is to provide a simple and dependable apparatus and circuit arrangement for controlling in a thoroughly practical way the high tension circuit or circuits, more articularly the discharge circuit of a highvoltage permittor or condenser associated with the X-ray tube for energizing the latter. and moreover to effect such a control in a manner capable of giving the X-ray emanations the desired characteristics.

Other objects and advantages and other uses for which the invention is adapted will be in part specifically pointed out in the following description thereof or will be apparent from such descri tion.

The invention accordingly consists in the features of construction, combinations of elements. and arrangements of parts as will be exemplified in the structure to be hereinafter described and the scope of the ap lication of which will be indicated in the ollowing claims.

In order that the invention may-be readily understood and its practical advantages more fully appreciated reference may be had to the accompanying drawing in which Fig. 1 illustrates more or less schematicaly one form of embodiment of the same; an

Fig. 2 is a modification showing means Referring now to the drawing: 1, 2, 3, 4 and 5 designate multiple circuits which are connected with the low voltage supply meme 6. The circuit 1 comprises a ste down transformer the purpose of which is to heat the cathode filament 7 of the kenotron 8. A variable reactance 9 in series with the fprimary 10 is provided for the urpose o hmitmg the current throu h the ament 7 which is connected across e secondary 11 of said transformer. The middle polntof the secondary 11 is connected to the unction point 12 which is grounded at 13.

The circuit 2 comprises a she -d0wn transformer the function of which 1s to heat the cathode filament 14 of the X-ray tube designated as a whole by 15. In series with the primary 16 of the said transformer is a variable reactance 17 for controlling the current through the filament 14 which is connected across the secondary 18 of said trans former. The transformer windings are insulated from each other for the voltage of excitation of the X-ra tube.

The circuit 3 comprises 9. etc -down transformer which heats the cathodb filament 19 of the magnetron which is designated as a whole by 20. A variable reactance 21 is provided in series with the transformer primary 22 for the purpose of controlling the current through the filament 19 which is connected across the transformer secondary 23. The transformer windings 22 and. 23 are insulated from each other for the full voltage of the X-ray tube excitation.

The circuit 4 comprises a transformer the purpose of which is to insulate the supply voltage from the X-ray tube voltage of excitation. The primary 24 of this transformer is insulated therefore from the secondary 25 for the full X-ray tube excitation voltage. A synchronous motor 26 is connected to the secondary 25 of this transformer. The said synchronous motor has direct connection with the current generator 27 which is couglad to a rotary switch designated as a whole y 28. Said generator supplies through the switch 28 the magnetizing current for the solenoid 29 of the magnetron previously referred to.

The said switch comprises two circular ring sectors 29 and 30 with a resistor 31 connected across the same. The rotatable arm 32 of insulating material carries a contactor 33 of metal ada ted to contact with the sectors 29 and 30 t ereby shunting the resistor 31. The arm 32 with the contactor 33 carried thereby is driven by the synchronous motor 26 t rough gears having such ratio as will give the desired speed of rotation.

The circuit 5 comprises a step-up transformer the primary and secondary windings of which are designated respectively 34 and 35. This transformer is for the purpose of charging the hi h voltage ermittor 36 unidirectionally. in order t at the drawin may be sim lo I have shown means for e fecting hal -wave rectification only, which means com rises the kenotron 8. To the anode 37 0 the said kenotron one side of the transformer secondary is connected. Connection is made from the center of the transformer seconds 11 to the junction 12 and to one side of e permittor 36 which side is grounded at 13. The other side of the transformer secondary 35 is connected to the insulated side of the ermittor 36 through a high resistor 38 an low resistor 39.

The discharge circuit of the permittor 36 is from the insulated side thereof through the low resistor 39 to motion point 40, and thence to the center 0 the transformer secondary 23, to the cathode filament 19 of the magnetron 20, to the anode 41 to the center of the transformer secondary 18 to the cathode 14 of the X-ray tube 15, from the anticathode 42 to junction point 12 and thence to the opposite or grounded side of the said rmittor 36.

The -ray tube is of the water-cooled anticathode type, the" water inlet and outlet being indicated at 43 and 44.

The 0 eration of the apparatus or system is as fo lows: The magnetron constitutes an electric valve which is 0 rated by a magnetic field. Its characteristic is such that if a constant voltage is impressed between the incandescent cathode 19 and the cold anode 41 the current that flows through the tube is not afi'ected by a magnetic field which is weaker than a certain critical value but falls to zero if the magnetic field is increased beyond such critical value. Therefore, during that art of a revolution of the contactor 33 in w ich it is in contact with the sector rings 29' and 30 and in shunt relation to the resistor 31 the ma etizing current impressed on the solenold 29 by the generator 27 is of maximum value. The magnetic field at that time or during such period is greater than the critical value we viously referred to and in consequence of which no current will flow throu h the magnetron. During this period the high volta permittor 36 is charged unidirectlonally the transformer secondary 35 through kenotron 8, as will be understood by those skilled in the art.

When the contactor 33 is out of contact with the sector rin 29 and 30 and out of shunt relation wit respect to the resistor 31; that is, during the period that the said contactor is moving between and out of contact with the adjacent o posing ends of the sectors 29 and 30, then the magnetizing current impressed on the solenold 29 by the generator 26 falls to a value such thatthe magnetic field is below the critical value previously referred to, in consequence of which current may flow through the magnetron. At this time. or during this tied the permittor 36 discharges throng the magnetron and the X-ray tube. It will be apparent from the disclosure of the drawing and from the foregoing description that the cycle is capable of continuous periodic repetition.

If a single X-ray beam is desired the manuall operable switch which is shown schematically in Fig. 2 may be substituted for the switch 28 of Fig. 1.

In said Fig. 2, 27 designates the direct current generator the circuit of which comprises a resistor 45 which is ada ted to be shunted by the manually opera le switch oonsistin of the metallic contactor 46 and the ban e 47 of insulatin material. The said handle 47 must aflor insulation suf- 1liicient for the X-ray tube voltage of excitaion.

The operation of the structure shown in Fig. 2 is as follows: When the switch is closed the contactor 46 is, as stated, in shunt relation to the resistor 45, which permits maximum magnetizing current to flow through the solenoid 29. As the flow of maximum current through said solenoid produces the maximum magnetic field (greater than the critical value previously referred to) 'no current flows at such time through the magnetron. During this cried the permittor 36 is charged as descri d in connection with the description of the system as illustrated in Fig. 1. When the switch is o ened as shown in Fig. 2 the ma netic fie (1 falls to a value below the critica value and current will flow through the magnetron 20 and the X-ray tube 15.

In order that the drawing as well as the description may be simplified I have shown but one X-ray tube. It is to be understood, however, that a plurality of tubes in multiple may be operated in series with a that-- mionic valve.

It is also to be understood that this invention is not limited to the use of a ma netron in the discharge circuit of thelng voltage permittor '36 and that any suitable type of vacuum thermionic valve may be used, such for example as a photron.

It is not deemed to be necessar to explain mathematically'or otherwise t e manner in which the proper constants of the permittor dischar e circuit are chosen to predetermine the uration and intensity of the X-ray beam as those skilled m the art will, in view of the foregoing, understand the efi'ects o'ffilpermittance, resistance, in-

ductance and ament electron evaporation.

As many possible embodiments may be made of the above invention and as many changes might be made in the embodiment above set forth, it is to be understood that all matter hereinbefore set forth or shown in the accompanying drawing, is to be interpreted as llustrative and not m a limiting sense.

Having thus described my invention, what I claim and desire to secure by Letters Patent is:

1. In X-ray ap aratus, 1n combinatlon, a permittor adapts to be charged at relatively, high voltage; means for chargin said permittor; a discharge circu1t for em permittor having included therein an X-ray tube and a thermionic valve for controlling said circuit; and means for periodically aflecting an element of said valve to change the conductivity of the latter and for thereby causing periodic discharge of said permittor.

2. In X-ray ap aratus, in combination, a permittor adapter to be charged at relatively high voltage; a source of relatively high alternating potential for charg1ng said permittor: rectifying means interposed between said permittor and said source a discharge circuit for said permittor having included therein an X-ray tube and a thermionic valve for controlling said circu t; and synchronously effective means for periodicallv affecting an element of sald valve to change the conductivity of the latter and for thereby causing periodic discharge of sald permittor.

3. In X-ray apparatus, in combination, a permittor adapted to be charged at relatively high voltage; means for chargln said permittor; a discharge circuit for sai permlttor having included therein an X-ray tube and a thermionic valve for controlling said 011- cuit; and mechanically driven means for controlling the periodicity of operation of said valve.

4. In X-ray apparatus, in combination, a permittor adapted to be charged at relat1ve 1y high voltage; means for charging sald permittor: a discharge circuit for said permittor having included therein an X-ray tube and a thermionic valve for controlling said circuit; means including a switch adapted when said switch is in one position, to afl ect an element of said valve to make the latter conductive and, when said switch is in another position to afiect an element of said valve to make the latter non-conductive; and means for successively moving said switch from one position to another.

5. In X-ray apparatus, in combination, an X-ray tube, means for maintaining the filament cathode of'said tube at a temperature suin'cient for electron emission, a permittor ada ted when charged to discharge through said X-ray tube; an electrical valve connected in circuit with said permittor and said X-ray tube for controlling the discharge of said permittor through said tube, and a periodically operative switch for controlling the operation of said valve.

6. In X-ray apparatus, in combination, a permittor adaptedto be charged at relatively high voltage; means for charging said permittor; a discharge circuit for said permittor having included therein an X-ray tube and a thermionic valve for controlling said circuit;,a resistance connected to one element of said thermionic valve; and means for periodically changing said resistance, thereby to periodically ailect said element and the operation of said valve.

7. In X-ray apparatus, in combination, an X-ray tube; a source of relatively high potential for energizing said tube; a device having a space discharge path therein connected in circuit with said source and with said tube; and means for periodically varying the conductivity of said space discharge path, thereby to affect periodic energization of said X-ray tube.

8. .An X-ray beam generator which comprises in combination an X-ray tube, means for maintaining the cathode of said tube at a temperature suflicient for electron emission, a high voltage permittor. means for charging said permittor, a discharge circuit for said permittor, which circuit includes in series a magnetron and the said tube, and means for controlling the said magnetron to permit periodic discharge of current from the said permittor therethrough and through the said tube, whereby periodic intense X-ray beams are generated.

9. An X-ray beam generator which comprises in combination a high voltage permittor, means for charging said permittor, a magnetron, an X'ray tube, a circuit conmeeting the said permittor and magnetron and X-ray tube in series, means for heating the cathode of the said magnetron, and means for controlling the flow of current through the solenoid of said magnetron, whereby the discharge of current through the said permittor circuit is controlled.

10. In X-ray apparatus, in combination, an X-ray tube; a source of relatively high potential for energizin said tube; a threeelement electronic device having an electronic conduction path between two of its elements under the control of the third ele ment and connected in circuit with said source of otential and said tube; and means for -perio ically affecting said third element of said device, thereby to cause periodic energization of said X-ray tube.

11. In X-ray apparatus, in combination, an X-ray tube; means including a source of alternating potential and rectifying means for energizing said X-ray tube; means having an electronic conduction path therein and connected so that said path is included in the circuit through which said X-ray tube is ener ized; and synchronously operated means or eriodically affecting the conductivity of t e conduction path of said lastmentioned means.

12. In X-ray apparatus, in combination, an X-ray tube connected in a circuit having included therein a source of potential adapted, when effective, to cause said tube to emanate rays; a device having a cathode and an anode connected to control said circuit and having electromagnetic means for controlling the conductivity of the space between said cathode and anode; and means for controlling the energization of said electroma etic means.

13. n X-ray apparatus, in combination, an X-ray tube connected in a. circuit having included therein a source of potential adapted, when eflective, to cause said tube to emanate rays; a device having a cathode and an anode connected to control said circuit and having electromagnetic means for controlling the conductivity of the space between said cathode and anode; a source of current for supplying energy to said electromagnetic means; and means for perioditally varying the energy supplied to said electromagnetic means.

14. In X-ray apparatus, in combination, an X-ray tube connected in a circuit having included therein a source of potential adapted, when effective, to cause said tube to emanate rays; a device having a cathode and an anode connected to control said circuit and having electromagnetic means for controlling the conductivity of the space between said cathode and anode; a source of current for supplying energy to said electromagnetic means; a resistance connected to affect the current flow to said electromagnetic means; and means for short-circuiting said resistance.

1%.; In X-ray apparatus, in combination, an -ray tube connected in a circuit having included therein a source of potential adapted, when efl'ective, to cause said tube to emanate rays; a device having a cathode and an anode connected to control said circuit and having electromagnetic means for controlling the conductivity of the space between said cathode and anode; a source of currentfor supplying energy to said electromagnetic means; a resistance connected to afl'ect the current flow to said electromagnetic means; and means for periodicaly affectin said resistance.

16. n X-ray apparatus, in combination, an x-eaiy tube connected in a circuit having mclud therein a source of potential adapted, when efiective, to cause said tube to emanate rays; a device having a cathode and an anode connected to control said circuit and having electromagnetic means for controlling the conductivity of the space between said cathode and anode: and means for eriodically changing the magnetic field pro need by said electromagnetic means from a value such that the conductivity of said device is suflicient to permit said source of potential to be efiective to a value such :hat said device is substantially non-conduc- 17. In X-ray apparatus, in combination, an X-ray tube; a transformer having its high tension winding connected across the electrodes of said X-ray tube throu h a rectifying device and through an e ectronic conduction valve; and means for periodically causing said valve to become conductive, thereby to effect periodic energization of said tube.

18. In X-ray apparatus, in combination, an X-ray tube connected in a circuit having included therein a source of potential adapted, when effective, to cause said tube to emanate rays; a device having a cathode and an anode connected to control said circuit and having an electro-responsive element for controlling the conductivity of the space between sai cathode and said anode; a source of potential for affecting said controlling element; and means for controlling the potential impressed upon said element.

19. In X-ray apparatus, in combination, an X-ray tube connected in a circuit having included therein a source of potential adapted, when efl'ective, to cause said tube to emanate rays; a device having a cathode and an anode connected to control said circuit and having an electro-responsive element for controlling the conductivity of the space between said cathode and said anode; a source of potential for affecting said controlling element, a resistance for affecting the potential impressed upon said element; and means for controlling said resistance.

20. In X-ray apparatus, in combination, an X-ray tube connected in a circuit having included therein a source of potential adapted, when effective, to cause said tube to emanate rays; a device having a cathode and an anode connected to control said circuit and having an electro responsive element for controlling the conductivity of the space between said cathode-and said anode; a source of potential for affecting said controlling element; and means for periodically changing the potential impressed upon said controlrling element.

21. An X-ray beam generator of high power comprising, in combination, an Ix-ray tube having a cathode filament, a high voltage permittor adapted to be discharged through said tube, means for charging said permittor, means for automatically preventing the discharge of said permittor through the said tube when the said permittor is being charged and for thereafter automatically causing discharge of the said permittor through the said tube.

In testimony that I claim the foregoing as my invention, I have hereunto signed my name this 13th day of February, 1924.

FRANKLIN S. SMITH.

e aid cathodeand said anode; a source ermittor, means for automatically preventb i iid te ntial for affecting said controlling eleihg the discharge of said permlttor throutgh ment; and means for periodically changing the said tube when the said permittor 1s tethe potential impressed upon said controlmg charged and for thereafter automa 1:

b lin element. cally causing d scharge of the said permittoi 2 1. An X-ray beam generator of high through the said tube. power comprising, in combination, an )x-ray In testimony that I claim the foregoing tube having a cathode filament, a high voltas my Invention, I have hereunto signed my age permittor adapted to be discharged name this 13th day of February, 1924. through said tube, means for charging said FRANKLIN S. SMITH.

DISCLAIMER 1,647,477.Franklin S. Smith, Brooklyn, N. Y. X-RAY-BEAM GENERATOR. Patent dated November 1, 1927. Disclaimer filed February 5, 1930, by the patentee, assignee, Products Protection Corporation, assenting and concurring.

Hereby enters the following disclaimer:

1. Whereas claims 7, l0, and 11, after setting forth an X-ray tube and a source of potential for energizin the tube, specify a device or means connected in circuit with said source and wit said tube (claim 7), or connected in circuit with said source of potential and said tube (claim 10), or connected so that said path (the electronic conduction path of said means) is included in the circuit through which said X-ray tube is energized (claim 11), and whereas the above-quoted expressions are possibly susceptible of too broad an interpretation and, when so interpreted, are liable to cover or include elements and/or arrangements not intended to be covered by these terms, such as an arrangement like that disclosed and described in German Patent No. 316,105 to Siemens and Halske, ausgegeben November 21, 1919 (which, incidentally, does not suggest or disclose my invention), wherein a thermionic valve is utilized, in place of the usual vibrating interrupter, in the low volta e or so-called primary circuit of an induction coil whose high voltage or socalled seconda winding is described as being connected to an X-ray tube, the liability to sue possible interpretation not being intended or foreseen and thus being accidental, I hereby disclaim any such broad meaning or interpretation of the above-quoted terms as will cover or include thereby such an arran ement as is disclosed in the above-mentioned German Letters Patent and, to c arify the nature of this disclaimer, I disclaim,in so far as claims 7, 10, and ll are concerned, any apparatus in which the device or means, such as the three-element electronic device of claim 10 for example, either is not connected directly in the high voltage energizing circuit of the X-ray tube or is not connected to form part of a circuit operating at a high voltage substantially on the order of the operating voltage of the X-ray tube.

2. Whereas claims 18, 19, and 20, after setting out an X-ra tube connected in a circuit having included therein a source of potential adapte when effective, to cause said tube to emanate rays, specify a device, which is to have a cathode and an anode, connected to control said circuit, and whereas the above-quoted expression is possibly susceptible of too broad an interpretation and, when so interpreted, is liable to cover elements and/or arran ements not intended to be covered by this expression, such as an arran ement disc osed and described in German Patent No. 316,105 to Siemens and Hals e, ausgegeben November 21, 1919 (which, incidentally does not sug est or disclose my invention), wherein a thermionic valve is substituted for the usua vibrating interrupter in the low voltage or so-called primary circuit of an induction coil whose high voltage or so-called secondary winding is connected to an X-ray tube, the liability to such possible interpretation not being intended nor foreseen and thus being accidental, I hereby disclaim any such broad meaning or interpretation of the above-quoted term as will cover or include thereby such an arrangement as is disclosed-in the above-mentioned German Letters Patent and, to clarify the nature of this disclaimer, I disclaim, in so far as claims l8, l9, and 20 are concerned, any apparatus in which the device or means, such as the three-element device of these claims, either does not control the high voltage X-ray tube discharge or energizing circuit by being connected directly in t at high voltage circuit or does not control the said discharge or energizing circuit by being connected to form part of a control circuit 0 crating at a high voltage substantially on the order of the operating voltageof tli e X-ray tube.

[O flicial Gautte February 25, 1930.]

DISCLAIMER 1,647,477.Franklin S. Smith, Brooklyn, N. Y; X-RAY-BEAM GENERATOR. Patent dated November 1, 1927. Disclaimer filed February 5, 1930, by the patentee, assignee, Products Protection Corporation, assenting and concurring.

Hereby enters the following disclaimer:

1. Whereas claims 7, 10, and 11, after setting forth an X-ray tube and a source of potential for energizing the tube, specify a device or means "connected in circuit with said source and with said tube (claim 7), or connected in circuit with said source of potential and said tube (claim 10), or connected so that said path (the electronic conduction path of said means) is included in the circuit through which said X-ray tube is energized (claim 11), and whereas the above-quoted expressions are possibly susceptible of too broad an interpretation and, when so interpreted, are liable to cover or include elements and/or arrangements not intended to be covered by these terms, such as an arrangement like that disclosed and described in German Patent No. 316,105 to Siemens and Halske, ausgegeben November 21, 1919 (which, incidentally, does not suggest or disclose my invention), wherein a thermionic valve is utilized, in place of the usual vibratin interrupter, in the low voltage or so-called primary circuit of an induction coil w ose high voltage or socalled secondary winding is described as being connected to an X-ray tube, the liability to such possible interpretation not being intended or foreseen and thus being accidental, I hereby disclaim any' such broad meaning or interpretation of the above-quoted terms as will cover or include thereby such an arran ement as is disclosed in the above-mentioned German Letters Patent and, to c arify the nature of this disclaimer, I disclaim, in so far as claims 7, 10, and llare concerned,

any apparatus in which the device or means, such as the three-element electronic device of claim 10 for example, either is not connected directly in the high voltage energizing circuit of the X-ray tube or is not connected to form part of a circuit operating at a high voltage substantially on the order of the operating voltage of the X-ray tube.

2. Whereas claims 18, 19, and 20, after setting out an X-ra tube connected in a circuit having included therein a source of potential adapte when effective, to cause said tube to emanate rays, specify a device, which is to have a cathode and an anode, connected to control said circuit, and whereas the above-quoted expression is possibly susceptible of too broad an interpretation and, when so interpreted, is liable to cover elements and/or arran ements not intended to be covered by this expression, such as an arran ement disc osed and described in German Patent N 0. 316,105 to Siemens and Hals e, ausgegeben November 21, 1919 (which, incidentally, does not sug est or disclose my invention), wherein a thermionic valve is substituted for the usua vibrating interrupter in the low voltage or so-called primary circuit of an induction coil whose high voltage or so-called secondary winding is connected to an X-ray tube, the liability to such possible interpretation not being intended nor foreseen and thus being accidental, I hereby disclaim any such broad meaning or interpretation of the above-quoted term as will cover or include thereby such an arrangement as is disclosedin the above-mentioned German Letters Patent and, to clarify the nature of this disclaimer, I disclaim, in so far as claims 18, 19, and 20 are concerned, any apparatus in which the device or means, such as the three-element device of these claims, either does not control the h voltage X-ray tube discharge or energizing circuit by being connected directly in t at high voltage circuit or does not control the said dlscharge or energizing circuit by being connected to form part of a control circuit ggerating at a high voltage substantially on the order of the operating voltage of e X-ray tube.

Gazette February 25, 1.980.] 

